Ore-concentration process



Sept. 16, 1924. 1,508,478

W. A. SCOTT ORE CONCENTRATION PROCESS Filed NOV. 12 1917 Patented Sept.16, 1924.

-UlTED FFEE.

WALTER A. SCOTT, OF CHICAGO, ILLINOIS, ASSIGNOR TO MINERALS SEPARATIONNORTH AMERICAN CORPORATION, A CORPORATION OF MARYLAND.

ORE-CONCENTRATION PROCESS.

Application filed November 12, 1917. Serial No. 201,463.

T40 all whom it may concern.

Be it known that I, WALTER A. Soon, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in an Ore-ConcentrationProcess, of which the following is a specification.

My invention is an improved flotation process. In the flotation processas previously practiced, as is well known, certain reagents or modifyingagents generally termed oils, although many of such substances are notoils, are added to a freely flowing ore pulp whereupon the introductionof air or some other gas into the pulp gives rise to the formation ofbubbles which collect the desired mineral, generally metalliferoussulphides, and reject the gangue. The modifying agents used for thisgreat variety of oils, animal, vegetable and mineral oils, coal and woodtar and derivatives thereof, various alcohols, hydroxyl compounds andother substances, all of which I refer to herein, for the sake of brevitas oils. Air, of course, is the most availa le gas and the one generallyused, but in referring to air herein I include all gases which have asimilar action.

Heretofore the air necessary in the operation of the process has beenintroduced into the ore pulp either by mechanical agitation which hasthe effect of introducing air from the atmosphere and beating it intothe pulp,

or by introducing air under pressure into the pulp through a porousmedium forming part of the vessel in which the pulp is con tained.Detailed explanation of the flotation process as heretofore practiced isun- 40 necessary in view of the fact that the process is widely knownand described in many patents and publications.

In the mechanical agitation method of introducing air the mechanicalagitation imparted to the pulp for that purpose is suflicient tothoroughly disseminate the oil through the pulp, such distribution ofthe .oil being necessary in order that it may accomplish its function.In the method of introducing air through a porous medium it is usual toadopt independent means for mixing the oil and such independent meanspurpose comprise a 1 have heretofore taken the form of mechanicalagitation sufficient to disseminate the oil and pro-aerate the pulp.

I have ascertained that the oil performs its principal, if not its only,function in the film surrounding the air bubbles and my inventionconsists in introducing the oil in such manner that it is supplieddirectly to the bubble films Without the necessity of disseminating theoil through the entire body of ore pulp. My invention consists in usinga volatile oil, impregnating the air with the gasified volatile oil, andintroducing the gaseous mixture of air and oil into the pulp whereuponsufficient of the oil collects in the bubble films to effect the desiredfunction. When operating according to my invention the necessity ofmechanical agitation for the purpose of mixing the oils with the entirebody of ore pulp is dispensed with and the amount of oil necessary forthe purpose is greatly diminished in quantity by reason of the fact thatthe oil is applied directly to the bubble films where it is needed,without the necessity of distributing the-oil throughout the body of theore pulp in order to accomplish that purpose.

have discovered, as set forth in my Patents 1,246,665 of November 1-7,1917, and 1,261,303 of April 2, 1918, that it is unnecessary to mix oilsor other so-called modifying agents with the ore pulp in order to floatthe metalliferous mineral, but that flotation can be effected with equalor greater efficiency by mixing the modifying agent in gaseous form withthe air which is introduced into the pulp for the purpose of theflotation process.

The gaseous modifying agent used may be either the vapor of a substancewhich is liquid under ordinary conditions of temperature and pressure orsome constituent of such substance, or, the gaseous modifying agent maybe a substance which under the ordinary conditions of temperature 'and'have described the introduction of such vaporized or gaseous modifyingagents into an ore pulp by means either of mechanical agitation havingthe effect of introducing the vapors or gases in and beating them intothe pulp or of a porous medium septum through which the vapors or gasesare introduced into the pulp. This application is directed to themechanical agitation method of introducing modifying vapors or gases ofthe kind above referred to wherein the pulp is subjected to mechanicalagitation having the effect of drawing in and beating into the ore pulpthe vaporized or gaseous substances.

For the purpose of carrying my invention into practice it is onlynecessary to provide an agitation vessel of the type ordinarily used andwell known, merel enclosing the top of the vessel and sup-p ying the gasto the space above the pulp in the enclosed top of the vessel.

The modifying gases delivered tothe apparatus may be prepared in anysuitable apparatus and may be vapors distilled from solid or liquidsubstances, the distillation being either the simple vaporization of thesubstances or their destructive distillation as in the cases of the gasformed from coal, asphaltic matter, gilsonite or other organicsubstances as hereinbefo-re referred to. The modifying as may be, andordinarily would be, supplie to the apparatus in admixture with air. Theeffect of the agitation of the pulp in the agitation vessel is to beatthe modifying gas or mixture of modifying gas and air into the ore pulp.When the pulp so treated flows into the usual spitzkasten a concentratefroth forms and floats in the usual way and is collected by skimming oroverflow.

l have shown in the accompanying drawing suitable means for carrying myinvention into practice. In this draw ing K re resents an agitationvessel, the agitator consisting of radial arms attached to the lower endof a shaft U which is rotated by means of power applied thereto fromsome convenient source. The vessel K is closed at the upper end exceptfor an air inlet V. At some suitable place in the upper part of thevessel K a container 0 is placed to hold the volatile oil, and, ifnecessary, steam pipes P may be supplied beneath the container O toassist in gasifying the oil. Adjacent the agitation vessel K is aspitzkasten Q provided with an overflow lip R and a launder S. Thespitzkasten is connected to the agitation vessel by a port T. Pulp maybe supplied to the agitation vessel through an inlet port M and thetailings discharged through the outlet N at the bottom of thespitzkasten. The supply and discharge of pulp from the apparatus is soregulated that the froth formed on the surface of the pulp in thespitzkasten flows over the lip R into the launders S.

In operation the air drawn into the pulp in the agitation vessel b theaction of the agitator enters through the inlet port V and becomes mixedwith gasified oil in the upper part of the agitation vessel and is thendrawn in and beaten into the pulp in the form of minute bubbles whichrise to the surface in the form of a froth in the spitzkasten Q. Thisfroth overflows into the launder S and may subsequently be broken downand the precipitated mineral recovered as concentrate and either treatedas finished concentrate or retreated for further purification, asdesired.

hat I claim is:

1. A process of concentrating ores comprising the operations ofintroducing a mixture of a non-frothing gas and a frothing agent ingaseous form into an ore pulp by agitating the ore pulpin the presenceof said gaseous mixture, whereby fine bubbles are formed to whichcertain mineral particles in the ore adhere as said bubbles pass throughthe pulp, causing said mineralbearing bubbles to form a froth above thepulp, and separating mineral carried by the froth from the remainder ofthe ore.

2. A process of concentrating ores comprising the operations ofintroducing a mixture of a non-frothing gas and a fnothing agent in theform of vapor into an ore pulp by agitating the ore pulp in the presenceof said gaseous mixture, whereby fine bubbles are formed to whichcertain mineral particles in the ore adhere as said bubbles pass throughthe pulp, causing said mineralbearing bubbles to form a froth above thepulp, and separating mineral carried by the froth from the remainder ofthe ore.

3. A process of concentrating ores comprising the operations ofintroducing a mixture of a non-frothing gas and a frothing agent ingaseous form into an ore pulp by agitating the ore pulp in the presenceof said gaseous mixture, whereby fine bubbles are formed to whichcertain mineral particles in the ore adhere, and then subjecting saidpulp to a state of substantial quiescence, thereby causing the formationof a mineral-bearing froth, and separating mineral carried by the frothfrom the remainder of the ore.

4. A process of concentrating ores comprising the operations ofintroducing a mixture of a non-frothing gas and a frothing agent in theform of vapor into an ore pulp by agitating the ore pulp in the presenceof said gaseous mixture, whereby fine bubbles are formed to whichcertain mineral particles in the ore adhere, and then subjecting saidpulp to a state of substantial quiescence, thereby causing the formationof a mineral-bearing froth, and separating mineral carried by the frothfrom the recondensible hydrocarbon in gaseous condimainder of the ore.tion by mechanically agitating and aerating 5. A flotation process ofore concentration the pulp in the presence of an atmosphere 10 involvingthe formation and separation of comprising such mixture. 5 amineral-bearin froth which includes the In testimony whereof, I havesubscribed step of introducing into the ore pulp fine my name. bubblesof a mixture of air with a readily WALTER A. SCOTT.

